BACKGROUND OF THE INVENTION
Field of the Present Disclosure
[0001] This disclosure relates generally to a method and apparatus for preparing sugarcane
stalks for subsequent, and more particularly to such methods and apparatus uniquely
adapted to separate the pith, rind, and epidermis components of sugarcane stalk in
a relatively efficient manner.
Description of Related Art including information disclosed under 37 CFR 1.97 and 1.98
[0002] Miller et al, US 3464877, discloses a process for treating sugarcane to obtain utilized strips of laterally
interconnected fibers of sugarcane rind by removing the pith from one side of the
rind and the epidermis material from the other side of the rind without disturbing
the rind fibers. The rind fiber strips are subjected to forming pressure and utilized
in a desired configuration.
[0003] Miller et al, US 3464881, discloses a structural building product manufactured from substantially uncrushed
and pith-free sugarcane rind fiber bundles, said product formed by applying heat and
pressure to the fiber bundles to bond and shape the bundles.
[0004] Tilby, US 3567510, discloses a method and apparatus for separating the pith, rind, and epidermis components
of split sugarcane stalk. Each split stalk portion is flattened and milled on the
pith side to separate pith from rind and milled on an opposite side to remove epidermis.
While the milling away of pith and epidermis is being effected, the rind is maintained
in a flattened condition and is positively engaged by rind, velocity-controlling,
gripping means which partially penetrate the ring periphery. The rind milling apparatus
is characterized by a milling roll having a plurality of generally radially extending
milling ridges. Each milling ridge has a planar milling side parallel to radial plan
of the roll and a peripheral, arcuate, rind-contacting which intersects the planar
milling side. The separator apparatus is incorporated with component conveying and
handling systems to facilitate the modular stacking of separator units. This modulator
stacking increases plant capacity and facilitates a secondary separation of residual
pith from rind, after the primary rind and pith separation has taken place.
[0005] Tilby, US 3698459, discloses a method for preparing a mass of randomly oriented, slender cane stalks
for subsequent processing at a selected location. The method is intended to deliver
the stalks in cleaned condition, chopped into uniform, relatively shorter lengths
and aligned longitudinally in their direction of motion.
[0006] Miller et al, US 3796809, discloses a process for sustaining livestock which involves providing the livestock
with a feed comprising sugarcane pith which contains substantially all of its naturally
present sugar juice and the fine inner fibers of the sugarcane stalk interior, but
which is substantially free from the highly lignified outer rind fibers of the sugarcane.
The sugarcane pith may be obtained by longitudinally opening the sugarcane without
expressing a significant amount of the sugar juice from the pith, and then separating
the pith from the outer rind fibers while retaining substantially all of the sugar
juice in the pith.
[0007] Tilby, US 4025278, discloses an apparatus for fabricating boards from sugarcane rind fibers wherein
a board is formed by accumulating a mass of sugarcane rind fibers in a collection
zone ahead of a horizontally reciprocable first-stage plunger that has a sweep face.
The first-stage plunger is shifted horizontally toward a fiber compression zone to
horizontally compact the sugarcane rind fibers and orient the fibers in vertical planes
disposed substantially parallel to the sweep face. A second-stage plunger is shifted
vertically downwardly from above the compression zone to push the horizontally compacted
sugarcane rind fibers downwardly into a generally vertical passage means while vertically
compressing the fibers. Consequently, the fibers are oriented in substantially horizontal
planes to define a board segment comprised of sugarcane rind fibers having their axes
disposed substantially parallel to the longitudinal axis of the board segment. The
steps of accumulating, horizontally shifting, and vertically shifting are repeated
to establish a column of abutting board segments in the extrusion passage. The board
segments are heated at a heating station to melt natural resinous binder substances
of the sugarcane rind fibers. Subsequently, the board segments are cooled at a setting
station location below said heating station to re-harden the natural resinous binder
substances and bind together the board segments into a unitary board structure.
[0008] Villavicencio, US 4231136, discloses that the pith removal from bagasse fiber is significantly enhanced by
the flow of fiber directly from one depithing zone to a second depithing zone without
any intermediate settling or pilings of the fiber. The fiber is maintained in a separated
condition during the flow from one depithing zone to another depithing zone. The result
is a bagasse fiber having a greater quantity of the pith removed with less fiber damage.
It is also advantageous to provide a number of conveyors to transport fibrous material
to a dual zone depithers and for the removal of depithed fiber and pitch from these
depithers. This reduces fiber handling before, during and after depithing.
[0009] Cundiff, US 4636263, discloses an apparatus and process for separating the pith from the bast of sweet
sorghum. Cut and headed stalks of the plant are arranged as a mat of the required
width on a conveyor and are forcibly advanced endwise into a rotating flail having
a multiplicity of dull beating or striking elements which catch the advancing stalks
against a stationary bar. The output of the process is a hail of small discrete particles
of wet sugar-laden pith used in the production of fuel alcohol and elongated strings
of fiber which had been the organized structural backbone of the plant. The quite
differently sized and shaped products are separated by vibrating screens or elutriation
in an air stream.
[0010] O'Sullivan, US 4961952, discloses a process for the solid phase fractionation of sugarcane into three fractions
comprising a fibrous fraction derived from the fibrous sclerenchyma cells from the
rind of the cane, a fibrous fraction derived from the fibrous sclerenchyma cells of
the fibrovascular bundles of the cane and a non-fibrous fraction derived from the
parenchyma cells of the cane. The process comprises the steps of (a) subjecting pieces
of the cane to a disintegrating force to cause a physical separation of the fibrous
sclerenchyma cells from the non-fibrous parenchyma cells, (b) drying the sugarcane
material, and (c) separating the sugarcane into the aforementioned three fractions.
[0011] Andrews, US 5106645, discloses a flour-type product derived from sugarcane which contains a high dietary
fiber concentration. This product is made by separating the pith of the sugar cane
from the rind and epidermal layer and then removing from the pith any rind residue
from a first stage separation and long fibrovascular bundles embedded in the parenchyma
cells of the pith. The clean pith is dried and milled to shred the walls of the parenchyma
cells into fiber having a length not exceeding 300 microns.
[0012] Tilby, US 5116422, discloses sugarcane separation equipment having movable carriages adjacent to the
tower-like central unit, such carriages being movable toward and away from such central
unit and having dermax removal apparatus thereon. Secondary and tertiary carriages
can be included on each side of the central unit to provide additional downstream
functions or earlier diversion of the product streams, as desired.
[0013] Tilby, US 5374316, discloses an apparatus and method for separating milled sugarcane pith from flattened
rind upon discharge from a depithing station. The method includes dividing the discharge
by a fixed deflector, preferably with a blunt upstream edge, into a primary pith flow
and a rind flow which includes a secondary pith flow, and thereafter removing pith
from the rind flow and diverting it to join pith from the primary pith flow. Preferred
embodiments capture the pith in interstices of a rotating brush which merges with
the secondary pith flow, turning such pith away from the rind flow, and then releasing
it.
[0014] Miller et al, CA 789214, discloses a process of segregating the rind of sugarcane stalks comprising removing
material from the exterior of a stalk of sugarcane to expose the exterior fiber bundles
of the rind, and removing from the interior fiber bundles substantially all of the
pith of the stalk.
[0015] Tilby et al, CA 1006410, discloses a method of processing sugarcane stalk material comprising the steps of
delivering sugarcane stalk material to a feed zone, resiliently gripping the sugarcane
stalk material at the feed zone between a pair of circumferentially grooved resilient
feed rolls having a plurality of tines projecting therefrom, rotating the resilient
rolls so that the tines impale the stalk material and cause a feeding of the stalk
material in response to frictional and tined engagement between the stalk material
and the grooved rolls, and separating components of the stalk material.
[0016] The related art described above discloses apparatuses and methods for separating
pith, rind, and epidermis components of a sugarcane stalk . However, the prior art
fails to disclose such an apparatus that is adjustable to accommodate a wide range
of stalk thicknesses while maintaining its ability to efficiently separate the sugarcane
components. In addition, the prior art fails to disclose such an apparatus that is
as compact, yet efficient, as the present invention. The present disclosure distinguishes
over the prior art providing heretofore unknown advantages as described in the following
summary.
BRIEF SUMMARY OF THE INVENTION
[0017] This disclosure teaches certain benefits in construction and use which give rise
to the objectives described below.
[0018] The stalk of a sugarcane plant includes an outer rind which is a hard, wood-like
fibrous substance. The rind surrounds a central core of pith, which bears nearly all
of the sugar juice from which various sugar products are made. In addition, the outer
surface of the rind has a thin, waxy epidermal layer, herein referred to simply as
the epidermis.
[0019] It has been recognized in the sugarcane industry that a number of very useful products
may be produced from sugarcane, other than simply sugar, if the sugarcane stalk is
first separated into its rind, pith, and epidermis components. The many useful end-products
made possible by such separation can provide great economic benefit. Such separation
provides significant efficiencies in the production of sugar as well.
[0020] Currently, the common method to separate these components involves a system that
includes a multi-step operation executed by various portions of a split-cane machine.
Sugarcane billets, i.e., cut lengths of cane stalk preferably about 25-35cm long,
are driven downwardly over a splitter to divide them lengthwise into semicylindrical
half billets. The two half billets of a split billet are then processed individually
by symmetrical downstream portions of a split-cane machine. The first of such downstream
portions of the separator is a depithing station which includes a cutting roll and
holdback roll for milling pith away from the rind of the half billet while simultaneously
flattening the rind. The next downstream portion is an epidermis removal station from
which the rind emerges ready for subsequent processing in a variety of ways, including
slitting, chipping, and/or many other processing steps. The pith is conveyed away
from the split-cane machine to an extraction station where its sugar juice is removed.
[0021] The prior art discloses split-cane machines that require a plurality of pith-removing
rolls in order to ensure that all of the pith is removed from the rind before further
processing is performed on the rind. The present invention improves on this by providing
a single set of pith-removing rolls and a deflector blade positioned to efficiently
mill away the pith from the rind.
[0022] Each pair of opposing rolls is adjustable in order to modify the amount of space
between the opposing rolls, enabling the present invention to accommodate and process
a wide range of sugarcane stalk thicknesses while maintaining its ability to efficiently
separate each one of the sugarcane components.
[0023] In addition, the present invention is much more compact than prior art split-cane
machines, and is able to efficiently separate the pith, rind, and epidermis components
while consuming significantly less power.
[0024] A primary objective inherent in the above described apparatus and method of use is
to provide advantages not taught by the prior art.
[0025] Another objective is to provide a split-cane apparatus that is adjustable in order
to accommodate a wide range of sugarcane stalk thicknesses while maintaining its ability
to efficiently separate each one of the sugarcane components.
[0026] A further objective is to provide such an apparatus that is able to efficiently separate
each one of the sugarcane components using a smaller number of rolls than the prior
art.
[0027] A still further objective is to provide such an apparatus that is able to efficiently
separate each one of the sugarcane components using significantly less power than
the prior art.
[0028] A still further objective is to provide such an apparatus that is smaller and more
compact than the prior art.
[0029] A still further objective is to provide such an apparatus that accomplishes the separation
and processing of sugarcane stalk in a single, self-contained, compact unit.
[0030] Other features and advantages of the present invention will become apparent from
the following more detailed description, taken in conjunction with the accompanying
drawings, which illustrate, by way of example, the principles of the presently described
apparatus and method of its use.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0031] Illustrated in the accompanying drawings is at least one of the best mode embodiments
of the present invention In such drawings:
[0032] Figure 1 is a mechanical schematic diagram of the presently described apparatus;
[0033] Figure 2 is a schematic diagram of a drive thereof having a plurality of synchronized
direct drive motors;
[0034] Figure 3 is a perspective view of a sugarcane billet of a type processed in the described
apparatus; and
[0035] Figure 4 is a perspective view thereof.
DETAILED DESCRIPTION OF THE INVENTION
[0036] The above described drawing figures illustrate the described apparatus and its method
of use in at least one of its preferred, best mode embodiment, which is further defined
in detail in the following description. Those having ordinary skill in the art may
be able to make alterations and modifications to what is described herein without
departing from its spirit and scope. Therefore, it must be understood that what is
illustrated is set forth only for the purposes of example and that it should not be
taken as a limitation in the scope of the present apparatus and method of use.
[0037] Described now in detail is a split-cane apparatus for separating pith 6, rind 8,
and epidermis 10 components of a sugarcane stalk, as shown in detail in Fig. 3. As
shown in Fig. 1, the apparatus comprises a frame 12 supporting and interconnecting
a plurality of components. In addition, as shown in Fig. 2, a separate drive 14 is
used for driving each one of the rotatable components. Preferably, each one of the
rotatable components is driven by a direct drive variable speed electric motor. Driving
the rotatable components in this way eliminates the need for gear boxes, belt drives,
and chain drives which can potentially create many problems, given that sugarcane
processing plants typically operate in areas having high levels of salt in the atmosphere.
Thus, direct drives provide a more efficient and reliable means for driving the rotatable
components. Clearly, the independent drive motors 14 are controlled by a controller
(not shown) to provide the necessary speed synchronization and differential speed
control. It should be noted that other means for driving the rotatable components
may be substituted.
[0038] As shown in Fig. 1, a pair of first feed rolls
16 are positioned for frictionally engaging opposing sides of a pre-cut length of sugarcane
stalk, herein referred to as a billet
2. The first feed rolls
16 are configured for guiding the billet
2 over a splitter blade
18 positioned for splitting the billet
2 longitudinally into two billet portions
4, as shown in Fig. 4. In the preferred embodiment, the splitter blade
18 has a cutting angle of 60 degrees. Preferably, the splitter blade
18 is vertically adjustable for accommodating billets of varying thicknesses. The two
billet portions
4 are then processed individually by symmetrical processing paths
20. For each one of the two processing paths
18, a pair of second feed rolls
22 are positioned for frictionally engaging opposing sides of one of the billet portions
4 and directing it along the corresponding processing path
20. Preferably, each one of the first and second feed rolls
16 and
22 provide a gripping surface which enables the first and second feed rolls
16 and
22 to frictionally engage the billet
2 more effectively. The gripping surface is preferably concrete nails embedded into
the first and second feed rolls
16 and
22 head first, such that a length of the tip of each one of the nails is exposed. However,
other types of gripping surfaces may be substituted.
[0039] A first holdback roll
24 and a first cutting roll
26 are adjustably spaced apart and positioned for receiving the billet portion
4 from the second feed rolls
22. The first holdback roll
24 and first cutting roll
26 are adapted for removing the pith
6 from the rind
8 while simultaneously flattening the rind
8. Preferably, the first holdback roll
24 rotates at a slightly slower speed than the first cutting roll
26. In addition, the first holdback roll
24 provides both circumferentially positioned teeth as well as longitudinally positioned
grooved teeth adapted for preventing acceleration of the billet portion
4 while the first cutting roll
26 is removing the pith
6. In one embodiment the first cutting roll
26 provides rows of 30 cutting teeth along the circumference of the first cutting roll
26, with an included angle of 12 degrees between each of the cutting teeth. In an alternate
embodiment, the first cutting roll
26 provides rows of 36 cutting teeth along the circumference of the first cutting roll
26, with an included angle of 10 degrees between each of the cutting teeth. It should
be noted that both the 30-tooth cutting roll and the 36-tooth cutting roll have the
same diameter; thus, they can be used interchangeably in the present invention with
no additional calibration. The prior art teaches similar teeth on both holdback rolls
and cutter rolls, including the shape and material that such rolls may be comprised
of. Please refer to
Tilby, U.S. 5,374,316 which is hereby incorporated by reference into this disclosure.
[0040] The position of the first cutting roll
26 is fixed, while the position of the first holdback roll
24 is laterally adjustable for increasing or decreasing the space between the first
cutting roll
26 and first holdback roll
24. This adjustability enables the present invention to accommodate billet portions
4 of various thicknesses.
[0041] A deflector
28 is positioned downstream from the first cutting roll
26. The deflector
28 provides a cutting edge
30 that is directed toward the first cutting roll
26 and positioned for removing pith remnants (i.e., any pith
6 that was not removed by the first cutting roll
26) from the rind
8. The deflector
28 is able to be adjusted slightly to increase or decrease the space between the cutting
edge
30 and the first cutting roll
26, in order to accommodate billet portions
4 of varying thicknesses. As shown in Fig. 1, the deflector
28 further provides a pith side
28A and a rind side
28B. The pith side
28A is adapted and positioned for directing the removed pith
6 along a pith processing path. The pith processing path transports the pith
6 to a centralized pith receiver
32 positioned between the symmetrical processing paths
20, as shown in Fig. 1. The pith receiver
32 may be a large container, a conveyor belt, or any other means known to persons of
ordinary skill to collect the pith 6 and prepare it for further processing. The rind
side
28B is adapted and positioned for directing the flattened rind
8 along a rind processing path, discussed below.
[0042] A second holdback roll
34 and a second cutting roll
36 are adjustably spaced apart and positioned for receiving the flattened rind
8 from the rind side
28B of the deflector
28. The second holdback roll
34 and second cutting roll
36 are adapted for removing the epidermis
10 from the rind
8. Preferably, the second holdback roll
34 rotates at a slightly slower speed than the second cutting roll
36. In addition, the second holdback roll
34 provides both circumferentially positioned teeth as well as longitudinally positioned
grooved teeth adapted for preventing acceleration of the billet portion
4 while the second cutting roll
36 is removing the epidermis
10. The second cutting roll
36 provides cutting teeth arrangements similar to that of the first cutting roll
26 described above.
[0043] The position of the second holdback roll
34 is fixed, while the position of the second cutting roll
36 is laterally adjustable for increasing or decreasing the space between the second
holdback roll
34 and second cutting roll
36. This adjustability enables the present invention to accommodate billet portions
4 of various thicknesses.
[0044] As shown in Fig. 1, at least one shredder disc
38 is positioned for receiving the separated epidermis
10 and rind
8 from the second cutting roll
36. In the preferred embodiment, at least two knurled shredder discs
38 are positioned in a stacked overlapping fashion in order to efficiently shred both
the epidermis
10 and rind
8.
[0045] As shown in Fig. 1, a perforated tumbling drum
40 is positioned for receiving both the shredded epidermis
10 and the shredded rind
8. A plurality of perforations
42 in the tumbling drum
40 are sized for separating the shredded epidermis
10 from the shredded rind
8 by allowing the shredded epidermis
10 to pass through the perforations
42 and into an epidermis receiver
44. In addition, the tumbling drum
40 is angled, allowing the shredded rind
8 to pass through an opening
46 in the tumbling drum
40 and into a rind receiver
48.
[0046] The present invention, as described above, is thus able to separate pith
6, rind
8, and epidermis
10 components of a sugarcane stalk. The method of doing so comprises the steps of: interconnecting
and arranging the frame
12 and the plurality of direct drives
14 with a plurality of components along a processing path
20; forcing the billet
2 with the first feed rolls
16 over the splitter blade
18; removing the pith
6 from the rind
8, and flattening the rind
8 using the first holdback roll
24 and first cutting roll
26; removing pith remnants from the rind
8 and directing the pith
8 and pith remnants to the pith receiver
32; removing the epidermis
10 from the rind
8 using the second holdback roll
34 and second cutting roll
36; shredding the epidermis
10 and rind
8 using the at least one shredder disc
38; and separating the shredded epidermis
10 from the shredded rind
8 using a tumbling drum
40.
[0047] The enablements described in detail above are considered novel over the prior art
of record and are considered critical to the operation of at least one aspect of the
apparatus and its method of use and to the achievement of the above described objectives.
The words used in this specification to describe the instant embodiments are to be
understood not only in the sense of their commonly defined meanings, but to include
by special definition in this specification: structure, material or acts beyond the
scope of the commonly defined meanings. Thus if an element can be understood in the
context of this specification as including more than one meaning, then its use must
be understood as being generic to all possible meanings supported by the specification
and by the word or words describing the element.
[0048] The definitions of the words or drawing elements described herein are meant to include
not only the combination of elements which are literally set forth, but all equivalent
structure, material or acts for performing substantially the same function in substantially
the same way to obtain substantially the same result. In this sense it is therefore
contemplated that an equivalent substitution of two or more elements may be made for
any one of the elements described and its various embodiments or that a single element
may be substituted for two or more elements in a claim.
[0049] Changes from the claimed subject matter as viewed by a person with ordinary skill
in the art, now known or later devised, are expressly contemplated as being equivalents
within the scope intended and its various embodiments. Therefore, obvious substitutions
now or later known to one with ordinary skill in the art are defined to be within
the scope of the defined elements. This disclosure is thus meant to be understood
to include what is specifically illustrated and described above, what is conceptually
equivalent, what can be obviously substituted, and also what incorporates the essential
ideas.
[0050] The scope of this description is to be interpreted only in conjunction with the appended
claims and it is made clear, here, that each named inventor believes that the claimed
subject matter is what is intended to be patented.
1. A split-cane apparatus for separating pith, rind, and epidermis components of a sugarcane
billet, the apparatus comprising:
a frame with a drive, the drive interconnected with a plurality of components arranged
along a processing path;
a pair of feed rolls operable in forcing the billet over a splitter blade;
a first holdback roll and a first cutting roll, operable in removing the pith from
the rind, and in flattening the rind;
a deflector operable in removing pith remnants from the rind and directing the pith
and pith remnants to a pith receiver;
a second holdback roll and a second cutting roll operable in removing the epidermis
from the rind;
a shredder disc operable in shredding the epidermis and rind; and
a tumbling drum operable in separating the shredded epidermis from the shredded rind.
2. The apparatus of claim 1 wherein the feed roll provides a gripping surface.
3. The apparatus of claim 1 wherein the holdback rolls provide circumferentially positioned
teeth, and longitudinally positioned grooved teeth.
4. The apparatus of claim 1 wherein the respective associated holdback rolls and cutting
rolls have a differential in rotational speed.
5. The apparatus of claim 1 wherein the cutting rolls have one of approximately 30 and
36 cutting teeth.
6. The apparatus of claim 1 wherein the splitter blade, the respective associated cutting
rolls and holdback rolls, and the deflector are each operably positionable to accommodate
billet size variations.
7. A split-cane method for separating pith, rind, and epidermis components of a sugarcane
billet, the method comprising the steps of:
a) interconnecting and arranging a frame and a drive with a plurality of components
along a processing path;
b) forcing the billet with a pair of feed rolls over a splitter blade;
c) removing the pith from the rind, and flattening the rind using a first holdback
roll and a first cutting roll;
d) removing pith remnants from the rind and directing the pith and pith remnants to
a pith receiver;
e) removing the epidermis from the rind using a second holdback roll and a second
cutting roll;
f) shredding the epidermis and rind using a shredder disc; and
g) separating the shredded epidermis from the shredded rind using a tumbling drum.
8. The method of claim 7 comprising the further step of engaging the billet with a gripping
surface of the feed roll.
9. The method of claim 7 comprising the further step of gripping the billet with circumferentially
positioned teeth, and longitudinally positioned grooved teeth of the holdback rolls.
10. The method of claim 7 comprising the further step of providing a differential in rotational
speed between the respective associated holdback rolls and cutting rolls.
11. The method of claim 7 comprising the further step of positionally adjusting positions
of the splitter blade, the respective associated cutting rolls and holdback rolls,
and the deflector to accommodate billet size variations.